In the century since, the technology has advanced slowly, but has been mainly used in clinical conditions to measure general brain activity – the technology has typically been too low-resolution, expensive and bulky for many other uses.

Now, however, the general advance in manufacturing techniques and software algorithms means that the price of implementing the technology is dropping rapidly. Though there are many companies moving into this field, the leaders are Neurosky, based out of San Jose, California.

"Yes, it's 60 years old, so the neuroscience community don't consider it cutting edge" says Tansy Brook, Communications Director of Neurosky "but when we talk about the consumer, it's very much cutting edge and it's accessible. It's taken that long to transition it to the market."

We, the consumers, love it. Neurosky's technology was behind sold-out Christmas crazes like Mattel's Mind Flex and the Star Wars Force Trainer game. If you're a Youtube fan, you've doubtless seen Neurowear.net's Necomimi Cat Ear gadget as well, a headband with cat ears that flex when the user concentrates. The devices have been featured on the Gadget Show, where the presenters used their headbands to control a crane moving shipping containers.

The Mindwave headset isn't just a pretty device

The mind-monitoring tech

What's unique about Neurosky's technology is that it uses a dry sensor on the forehead. Most EEGS rely on wet sensors going through the hair to measure the firing of neurons – indeed, clinical uses can involve invasive procedures, putting electrodes directly into the brain to identify the signal from individual.

Neurosky's kit, by restricting itself to just one dry non-invasive sensor on the forehead, can be calibrated in as little as five seconds (though it does limit the type of signals it can detect) and can be very cheap – as little as £100 for a headset.

The other unique element are those software algorithms and the API. Neurosky are working on the basis of selling their hardware, so they're keen to make it as easy as possible for developers to create applications that use their headsets.

When we met them at the Game Developers' Convention, they were selling their headsets at a discount to developers and instructing them in the usage of the API. They were even running a competition for the game developers with the best ideas that use their ECG (heart rate) monitor tech, with a big money prize. "They come up with things that we've never even thought of" says Brook.

Their technology has two algorithms; measuring concentration and meditation. "It was something we just happened across." says Brook "For example, in archery if you're about to take a shot, but you're very focussed and you're not relaxed at all, then you're stressed."

Working with the Neurosky headset allows you to train yourself to be focussed and relaxed at the same time, perfect for archery or other semi-meditative activities. For this reason, Neurosky has been working with several Olympics teams – China, US and UK – to improve their athletes' focus. "It's the first real-time feedback about your mind."

For great science!

Similarly, though some neuroscientists scoff at the limitations of the device, the low price, rapid results (compared to FMRI) and portability means that means it allows for mass experiments like never before, so other neuroscientists are returning to the tech, including Stanford University's Sleep Centre, where overnight stays can cost thousands of dollars.

"We have a lot of researchers who won't use our algorithms because they have their own", says Brook "They use the tech for data collection, because it's so much less expensive; with our Stanford professor, he can send his subjects home with a laptop and headset and collect data from them every night. Instead of being a shielded environment like FMRI, where your chin is strapped down and you can't really move, you can do it in a real world environment. The mobile headset also lets you combine sensors, so you have brainwave data, ECG, accelerometers and things like that."

Similarly, given the cheapness and portability of the devices, less hypothesis-driven research is possible; scientists can just take a large, balanced sample group of people, monitor them for a given period, and generate a database, before crunching it through a computer for trends that we might not even know existed.

The list of possible applications this suggests to us is immense; telekinesis, feedback loops, improving concentration, generating device empathy for user stress, monitoring health, and neuro-marketing are just a few ideas. There are limitations though; Neurosky aren't looking to get the device registered for medical use, as their target is the consumer market; they're happy to use that to build awareness of neuroscience instead.

Are game developers onboard?

Neurosky's own simple headband also has its own games, away from the rebranding of the toys. Game developer Myndplay creates Choose-Your-Own-Adventures that uses your brainwaves to change the direction of the story. Similarly, Interaxon developed a public game that let players control the lights on the CN tower and Niagra Falls in realtime.

Finally, Focus Pocus, a game based on fifteen years of ADHD research, lets hyperactive children pretend they're at Wizard school, whilst slyly training them to improve their concentration. "They help kids learn how to control their impulses, outside of a lab environment," says Brook "and reduce or eliminate medication completely, so you're naturally working out your kid's brain instead of putting him or her into a vegetative state. "

FocusPocus helps kids cope with ADHD

Unity, one of the leading game development suites, even has a plug-in to make integration easy. "To integrate the brainwave tech, it's less than a day." says Brook "One of our software engineers had ten minutes to do a presentation and he went, "here's how you connect it, here's how you integrate it. That's it." That's why we did the algorithms; you don't need any background in neuroscience to get it up and running."

As we were seeing the technology at the Game Developers Conference, we took the time to ask visiting developers what they thought of the tech. Two developers who'd seen the tech, or something similar, weren't overly positive. Joel Bylos of Funcom; "At the moment it is far too binary and unresponsive to be of much use... at the end of the day I feel like mouse and keyboard are still the best extension of our will into virtual worlds."

Similarly Frank Savage of Jumala thought that "the biggest issue developers face is translating the 'intention' of the mind state into an 'action' that makes sense within the context of a game. For example, just 'reading the mind' to turn left, stop, shoot, reload, move forward, etc. will be far fuzzier than the player's hands on a controller or even through Kinect. Until we can exceed tens of millisecond-level accuracy on interpreting the thoughts, things will stay as they are."

Thankfully, Neurosky is clear about the limitations of the technology for direct control, as Brook says; "That tech is available, but right now it's in an lab environment, and it's invasive; they go into the brain's grey matter. The thing I love about invasive VCI is that it shows you the potential for the technology, because they are looking at it on a cellular level. The limitations of EEG is that you have hair and skin and the skull, and smearing from the liquid between the skull and the brain, so it's like looking through water."

However, Frederick Wester, CEO of game publisher Paradox, wasn't aware of it but thought it had "great potential; we could use a telepathic user interface in our games." John Warren of Minicore echoed the Myndplay designs; "For narrative-based games, it could take the player's mood and use it to change the game in some way - either challenging or reinforcing the player's decisions. Games could become more difficult since, presumably, mind-control tech would allow faster decision-making in twitch situations."

Controllers will be the difference

They're not the only ones to show interest. Given the move to cloud-computing, the major differentiators of the next generation of consoles are likely to be unique interfaces, like the Wii U's strange controller – and what could be stranger than mind control? "

We've talked to all of the console providers and they're really positive." says Brook. "They're kinda like herding cats... ... getting the developers lined up to make the apps, getting the hardware integrated, the market educated... We're definitely going that direction."

EEG might not be accurate enough to read minds or new enough to make developers and neuroscientists think of it as sexy or cutting edge; but as a hundred-year-old technology that's now cheap, fast and easily understood, it's finally coming of age.